Added in API level 18

Summary: Constants | Inherited Constants | Methods | Inherited Methods

BluetoothGatt

Kotlin |Java

public final class BluetoothGatt
extends Object implements BluetoothProfile

java.lang.Object
↳	android.bluetooth.BluetoothGatt

Public API for the Bluetooth GATT Profile.

This class provides Bluetooth GATT functionality to enable communication with Bluetooth Smart or Smart Ready devices.

To connect to a remote peripheral device, create a BluetoothGattCallback and call BluetoothDevice#connectGatt to get a instance of this class. GATT capable devices can be discovered using the Bluetooth device discovery or BLE scan process.

Summary

Constants
`int`	`CONNECTION_PRIORITY_BALANCED` Connection parameter update - Use the connection parameters recommended by the Bluetooth SIG.
`int`	`CONNECTION_PRIORITY_DCK` Connection parameter update - Request the priority preferred for Digital Car Key for a lower latency connection.
`int`	`CONNECTION_PRIORITY_HIGH` Connection parameter update - Request a high priority, low latency connection.
`int`	`CONNECTION_PRIORITY_LOW_POWER` Connection parameter update - Request low power, reduced data rate connection parameters.
`int`	`GATT_CONNECTION_CONGESTED` A remote device connection is congested.
`int`	`GATT_CONNECTION_TIMEOUT` GATT connection timed out, likely due to the remote device being out of range or not advertising as connectable.
`int`	`GATT_FAILURE` A GATT operation failed, errors other than the above
`int`	`GATT_INSUFFICIENT_AUTHENTICATION` Insufficient authentication for a given operation
`int`	`GATT_INSUFFICIENT_AUTHORIZATION` Insufficient authorization for a given operation
`int`	`GATT_INSUFFICIENT_ENCRYPTION` Insufficient encryption for a given operation
`int`	`GATT_INVALID_ATTRIBUTE_LENGTH` A write operation exceeds the maximum length of the attribute
`int`	`GATT_INVALID_OFFSET` A read or write operation was requested with an invalid offset
`int`	`GATT_READ_NOT_PERMITTED` GATT read operation is not permitted
`int`	`GATT_REQUEST_NOT_SUPPORTED` The given request is not supported
`int`	`GATT_SUCCESS` A GATT operation completed successfully
`int`	`GATT_WRITE_NOT_PERMITTED` GATT write operation is not permitted

Inherited constants

From interface android.bluetooth.BluetoothProfile

`int`	`A2DP` A2DP profile.
`int`	`CSIP_SET_COORDINATOR` Coordinated Set Identification Profile set coordinator
`String`	`EXTRA_PREVIOUS_STATE` Extra for the connection state intents of the individual profiles.
`String`	`EXTRA_STATE` Extra for the connection state intents of the individual profiles.
`int`	`GATT` GATT
`int`	`GATT_SERVER` GATT_SERVER
`int`	`HAP_CLIENT`
`int`	`HEADSET` Headset and Handsfree profile
`int`	`HEALTH` This constant was deprecated in API level 29. Health Device Profile (HDP) and MCAP protocol are no longer used. New apps should use Bluetooth Low Energy based solutions such as `BluetoothGatt`, `BluetoothAdapter.listenUsingL2capChannel()`, or `BluetoothDevice.createL2capChannel(int)`
`int`	`HEARING_AID` Hearing Aid Device
`int`	`HID_DEVICE` HID Device
`int`	`LE_AUDIO` LE Audio Device
`int`	`SAP`
`int`	`STATE_CONNECTED` The profile is in connected state
`int`	`STATE_CONNECTING` The profile is in connecting state
`int`	`STATE_DISCONNECTED` The profile is in disconnected state
`int`	`STATE_DISCONNECTING` The profile is in disconnecting state

Public methods
`void`	`abortReliableWrite(BluetoothDevice mDevice)` This method was deprecated in API level 19. Use `abortReliableWrite()`
`void`	`abortReliableWrite()` Cancels a reliable write transaction for a given device.
`boolean`	`beginReliableWrite()` Initiates a reliable write transaction for a given remote device.
`void`	`close()` Close this Bluetooth GATT client.
`boolean`	`connect()` Connect back to remote device.
`void`	`disconnect()` Disconnects an established connection, or cancels a connection attempt currently in progress.
`boolean`	`discoverServices()` Discovers services offered by a remote device as well as their characteristics and descriptors.
`boolean`	`executeReliableWrite()` Executes a reliable write transaction for a given remote device.
`List<BluetoothDevice>`	`getConnectedDevices()` This method is deprecated. Not supported - please use `BluetoothManager#getConnectedDevices(int)` with `BluetoothProfile#GATT` as argument
`int`	`getConnectionState(BluetoothDevice device)` This method is deprecated. Not supported - please use `BluetoothManager#getConnectedDevices(int)` with `BluetoothProfile#GATT` as argument
`BluetoothDevice`	`getDevice()` Return the remote bluetooth device this GATT client targets to
`List<BluetoothDevice>`	`getDevicesMatchingConnectionStates(int[] states)` This method is deprecated. Not supported - please use `BluetoothManager.getDevicesMatchingConnectionStates(int, int[])` with `BluetoothProfile.GATT` as first argument
`BluetoothGattService`	`getService(UUID uuid)` Returns a `BluetoothGattService`, if the requested UUID is supported by the remote device.
`List<BluetoothGattService>`	`getServices()` Returns a list of GATT services offered by the remote device.
`boolean`	`readCharacteristic(BluetoothGattCharacteristic characteristic)` Reads the requested characteristic from the associated remote device.
`boolean`	`readDescriptor(BluetoothGattDescriptor descriptor)` Reads the value for a given descriptor from the associated remote device.
`void`	`readPhy()` Read the current transmitter PHY and receiver PHY of the connection.
`boolean`	`readRemoteRssi()` Read the RSSI for a connected remote device.
`boolean`	`requestConnectionPriority(int connectionPriority)` Request a connection parameter update.
`boolean`	`requestMtu(int mtu)` Request an MTU size used for a given connection.
`boolean`	`setCharacteristicNotification(BluetoothGattCharacteristic characteristic, boolean enable)` Enable or disable notifications/indications for a given characteristic.
`void`	`setPreferredPhy(int txPhy, int rxPhy, int phyOptions)` Set the preferred connection PHY for this app.
`boolean`	`writeCharacteristic(BluetoothGattCharacteristic characteristic)` This method was deprecated in API level 33. Use `BluetoothGatt#writeCharacteristic(BluetoothGattCharacteristic, byte[], int)` as this is not memory safe because it relies on a `BluetoothGattCharacteristic` object whose underlying fields are subject to change outside this method.
`int`	`writeCharacteristic(BluetoothGattCharacteristic characteristic, byte[] value, int writeType)` Writes a given characteristic and its values to the associated remote device.
`boolean`	`writeDescriptor(BluetoothGattDescriptor descriptor)` This method was deprecated in API level 33. Use `BluetoothGatt#writeDescriptor(BluetoothGattDescriptor, byte[])` as this is not memory safe because it relies on a `BluetoothGattDescriptor` object whose underlying fields are subject to change outside this method.
`int`	`writeDescriptor(BluetoothGattDescriptor descriptor, byte[] value)` Write the value of a given descriptor to the associated remote device.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          android.bluetooth.BluetoothProfile

`abstract List<BluetoothDevice>`	`getConnectedDevices()` Get connected devices for this specific profile.
`abstract int`	`getConnectionState(BluetoothDevice device)` Get the current connection state of the profile
`abstract List<BluetoothDevice>`	`getDevicesMatchingConnectionStates(int[] states)` Get a list of devices that match any of the given connection states.

Constants

CONNECTION_PRIORITY_BALANCED

Added in API level 21

public static final int CONNECTION_PRIORITY_BALANCED

Connection parameter update - Use the connection parameters recommended by the Bluetooth SIG. This is the default value if no connection parameter update is requested.

Constant Value: 0 (0x00000000)

CONNECTION_PRIORITY_DCK

Added in API level 34

public static final int CONNECTION_PRIORITY_DCK

Connection parameter update - Request the priority preferred for Digital Car Key for a lower latency connection. This connection parameter will consume more power than CONNECTION_PRIORITY_BALANCED, so it is recommended that apps do not use this unless it specifically fits their use case.

Constant Value: 3 (0x00000003)

CONNECTION_PRIORITY_HIGH

Added in API level 21

public static final int CONNECTION_PRIORITY_HIGH

Connection parameter update - Request a high priority, low latency connection. An application should only request high priority connection parameters to transfer large amounts of data over LE quickly. Once the transfer is complete, the application should request CONNECTION_PRIORITY_BALANCED connection parameters to reduce energy use.

Constant Value: 1 (0x00000001)

CONNECTION_PRIORITY_LOW_POWER

Added in API level 21

public static final int CONNECTION_PRIORITY_LOW_POWER

Connection parameter update - Request low power, reduced data rate connection parameters.

Constant Value: 2 (0x00000002)

GATT_CONNECTION_CONGESTED

Added in API level 21

public static final int GATT_CONNECTION_CONGESTED

A remote device connection is congested.

Constant Value: 143 (0x0000008f)

GATT_CONNECTION_TIMEOUT

Added in API level 35

public static final int GATT_CONNECTION_TIMEOUT

GATT connection timed out, likely due to the remote device being out of range or not advertising as connectable.

Constant Value: 147 (0x00000093)

GATT_FAILURE

Added in API level 18

public static final int GATT_FAILURE

A GATT operation failed, errors other than the above

Constant Value: 257 (0x00000101)

GATT_INSUFFICIENT_AUTHENTICATION

Added in API level 18

public static final int GATT_INSUFFICIENT_AUTHENTICATION

Insufficient authentication for a given operation

Constant Value: 5 (0x00000005)

GATT_INSUFFICIENT_AUTHORIZATION

Added in API level 33

public static final int GATT_INSUFFICIENT_AUTHORIZATION

Insufficient authorization for a given operation

Constant Value: 8 (0x00000008)

GATT_INSUFFICIENT_ENCRYPTION

Added in API level 18

public static final int GATT_INSUFFICIENT_ENCRYPTION

Insufficient encryption for a given operation

Constant Value: 15 (0x0000000f)

GATT_INVALID_ATTRIBUTE_LENGTH

Added in API level 18

public static final int GATT_INVALID_ATTRIBUTE_LENGTH

A write operation exceeds the maximum length of the attribute

Constant Value: 13 (0x0000000d)

GATT_INVALID_OFFSET

Added in API level 18

public static final int GATT_INVALID_OFFSET

A read or write operation was requested with an invalid offset

Constant Value: 7 (0x00000007)

GATT_READ_NOT_PERMITTED

Added in API level 18

public static final int GATT_READ_NOT_PERMITTED

GATT read operation is not permitted

Constant Value: 2 (0x00000002)

GATT_REQUEST_NOT_SUPPORTED

Added in API level 18

public static final int GATT_REQUEST_NOT_SUPPORTED

The given request is not supported

Constant Value: 6 (0x00000006)

GATT_SUCCESS

Added in API level 18

public static final int GATT_SUCCESS

A GATT operation completed successfully

Constant Value: 0 (0x00000000)

GATT_WRITE_NOT_PERMITTED

Added in API level 18

public static final int GATT_WRITE_NOT_PERMITTED

GATT write operation is not permitted

Constant Value: 3 (0x00000003)

Public methods

abortReliableWrite

Added in API level 18
Deprecated in API level 19

public void abortReliableWrite (BluetoothDevice mDevice)

This method was deprecated in API level 19.
Use abortReliableWrite()

For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`mDevice`	`BluetoothDevice`

abortReliableWrite

Added in API level 19

public void abortReliableWrite ()

Cancels a reliable write transaction for a given device.

Calling this function will discard all queued characteristic write operations for a given remote device.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

beginReliableWrite

Added in API level 18

public boolean beginReliableWrite ()

Initiates a reliable write transaction for a given remote device.

Once a reliable write transaction has been initiated, all calls to writeCharacteristic(BluetoothGattCharacteristic) are sent to the remote device for verification and queued up for atomic execution. The application will receive a BluetoothGattCallback#onCharacteristicWrite callback in response to every writeCharacteristic(android.bluetooth.BluetoothGattCharacteristic, byte[], int) call and is responsible for verifying if the value has been transmitted accurately.

After all characteristics have been queued up and verified, executeReliableWrite() will execute all writes. If a characteristic was not written correctly, calling abortReliableWrite() will cancel the current transaction without committing any values on the remote device.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`boolean`	true, if the reliable write transaction has been initiated

close

Added in API level 18

public void close ()

Close this Bluetooth GATT client.

Application should call this method as early as possible after it is done with this GATT client.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

connect

Added in API level 18

public boolean connect ()

Connect back to remote device.

This method is used to re-connect to a remote device after the connection has been dropped. If the device is not in range, the re-connection will be triggered once the device is back in range.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`boolean`	true, if the connection attempt was initiated successfully

disconnect

Added in API level 18

public void disconnect ()

Disconnects an established connection, or cancels a connection attempt currently in progress.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

discoverServices

Added in API level 18

public boolean discoverServices ()

Discovers services offered by a remote device as well as their characteristics and descriptors.

This is an asynchronous operation. Once service discovery is completed, the BluetoothGattCallback.onServicesDiscovered(BluetoothGatt, int) callback is triggered. If the discovery was successful, the remote services can be retrieved using the getServices() function.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`boolean`	true, if the remote service discovery has been started

executeReliableWrite

Added in API level 18

public boolean executeReliableWrite ()

Executes a reliable write transaction for a given remote device.

This function will commit all queued up characteristic write operations for a given remote device.

A BluetoothGattCallback#onReliableWriteCompleted callback is invoked to indicate whether the transaction has been executed correctly.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`boolean`	true, if the request to execute the transaction has been sent

getConnectedDevices

Added in API level 18

public List<BluetoothDevice> getConnectedDevices ()

This method is deprecated.
Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

Get connected devices for this specific profile.

Return the set of devices which are in state STATE_CONNECTED

Returns
`List<BluetoothDevice>`	List of devices. The list will be empty on error.

Throws
`UnsupportedOperationException`	on every call

getConnectionState

Added in API level 18

public int getConnectionState (BluetoothDevice device)

This method is deprecated.
Not supported - please use BluetoothManager#getConnectedDevices(int) with BluetoothProfile#GATT as argument

Get the current connection state of the profile

Parameters
`device`	`BluetoothDevice`: Remote bluetooth device.

Returns
`int`	State of the profile connection. One of `STATE_CONNECTED`, `STATE_CONNECTING`, `STATE_DISCONNECTED`, `STATE_DISCONNECTING` Value is `STATE_DISCONNECTED`, `STATE_CONNECTING`, `STATE_CONNECTED`, or `STATE_DISCONNECTING`

Throws
`UnsupportedOperationException`	on every call

getDevice

Added in API level 18

public BluetoothDevice getDevice ()

Return the remote bluetooth device this GATT client targets to

Returns
`BluetoothDevice`	remote bluetooth device

getDevicesMatchingConnectionStates

Added in API level 18

public List<BluetoothDevice> getDevicesMatchingConnectionStates (int[] states)

This method is deprecated.
Not supported - please use BluetoothManager.getDevicesMatchingConnectionStates(int, int[]) with BluetoothProfile.GATT as first argument

Get a list of devices that match any of the given connection states.

If none of the devices match any of the given states, an empty list will be returned.

Parameters
`states`	`int`: Array of states. States can be one of `BluetoothProfile.STATE_CONNECTED`, `BluetoothProfile.STATE_CONNECTING`, `BluetoothProfile.STATE_DISCONNECTED`, `BluetoothProfile.STATE_DISCONNECTING`,

Returns
`List<BluetoothDevice>`	List of devices. The list will be empty on error.

Throws
`UnsupportedOperationException`	on every call

getService

Added in API level 18

public BluetoothGattService getService (UUID uuid)

Returns a BluetoothGattService, if the requested UUID is supported by the remote device.

This function requires that service discovery has been completed for the given device.

If multiple instances of the same service (as identified by UUID) exist, the first instance of the service is returned.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.

Parameters
`uuid`	`UUID`: UUID of the requested service

Returns
`BluetoothGattService`	BluetoothGattService if supported, or null if the requested service is not offered by the remote device.

getServices

Added in API level 18

public List<BluetoothGattService> getServices ()

Returns a list of GATT services offered by the remote device.

This function requires that service discovery has been completed for the given device.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.

Returns
`List<BluetoothGattService>`	List of services on the remote device. Returns an empty list if service discovery has not yet been performed.

readCharacteristic

Added in API level 18

public boolean readCharacteristic (BluetoothGattCharacteristic characteristic)

Reads the requested characteristic from the associated remote device.

This is an asynchronous operation. The result of the read operation is reported by the BluetoothGattCallback#onCharacteristicRead(BluetoothGatt, BluetoothGattCharacteristic, byte[], int) callback.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`characteristic`	`BluetoothGattCharacteristic`: Characteristic to read from the remote device

Returns
`boolean`	true, if the read operation was initiated successfully

readDescriptor

Added in API level 18

public boolean readDescriptor (BluetoothGattDescriptor descriptor)

Reads the value for a given descriptor from the associated remote device.

Once the read operation has been completed, the BluetoothGattCallback.onDescriptorRead(BluetoothGatt, BluetoothGattDescriptor, int) callback is triggered, signaling the result of the operation.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`descriptor`	`BluetoothGattDescriptor`: Descriptor value to read from the remote device

Returns
`boolean`	true, if the read operation was initiated successfully

readPhy

Added in API level 26

public void readPhy ()

Read the current transmitter PHY and receiver PHY of the connection. The values are returned in BluetoothGattCallback#onPhyRead
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

readRemoteRssi

Added in API level 18

public boolean readRemoteRssi ()

Read the RSSI for a connected remote device.

The BluetoothGattCallback#onReadRemoteRssi callback will be invoked when the RSSI value has been read.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`boolean`	true, if the RSSI value has been requested successfully

requestConnectionPriority

Added in API level 21

public boolean requestConnectionPriority (int connectionPriority)

Request a connection parameter update.

This function will send a connection parameter update request to the remote device.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`connectionPriority`	`int`: Request a specific connection priority. Must be one of `CONNECTION_PRIORITY_BALANCED`, `CONNECTION_PRIORITY_HIGH` `CONNECTION_PRIORITY_LOW_POWER`, or `CONNECTION_PRIORITY_DCK`.

Returns
`boolean`

Throws
`IllegalArgumentException`	If the parameters are outside of their specified range.

requestMtu

Added in API level 21

public boolean requestMtu (int mtu)

Request an MTU size used for a given connection. Please note that starting from Android 14, the Android Bluetooth stack requests the BLE ATT MTU to 517 bytes when the first GATT client requests an MTU, and disregards all subsequent MTU requests. Check out MTU is set to 517 for the first GATT client requesting an MTU for more information.

When performing a write request operation (write without response), the data sent is truncated to the MTU size. This function may be used to request a larger MTU size to be able to send more data at once.

A BluetoothGattCallback#onMtuChanged callback will indicate whether this operation was successful.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`mtu`	`int`

Returns
`boolean`	true, if the new MTU value has been requested successfully

setCharacteristicNotification

Added in API level 18

public boolean setCharacteristicNotification (BluetoothGattCharacteristic characteristic, 
                boolean enable)

Enable or disable notifications/indications for a given characteristic.

Once notifications are enabled for a characteristic, a BluetoothGattCallback.onCharacteristicChanged(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, byte[]) callback will be triggered if the remote device indicates that the given characteristic has changed.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`characteristic`	`BluetoothGattCharacteristic`: The characteristic for which to enable notifications
`enable`	`boolean`: Set to true to enable notifications/indications

Returns
`boolean`	true, if the requested notification status was set successfully

setPreferredPhy

Added in API level 26

public void setPreferredPhy (int txPhy, 
                int rxPhy, 
                int phyOptions)

Set the preferred connection PHY for this app. Please note that this is just a recommendation, whether the PHY change will happen depends on other applications preferences, local and remote controller capabilities. Controller can override these settings.

BluetoothGattCallback#onPhyUpdate will be triggered as a result of this call, even if no PHY change happens. It is also triggered when remote device updates the PHY.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`txPhy`	`int`: preferred transmitter PHY. Bitwise OR of any of `BluetoothDevice.PHY_LE_1M_MASK`, `BluetoothDevice#PHY_LE_2M_MASK`, and `BluetoothDevice.PHY_LE_CODED_MASK`.
`rxPhy`	`int`: preferred receiver PHY. Bitwise OR of any of `BluetoothDevice.PHY_LE_1M_MASK`, `BluetoothDevice#PHY_LE_2M_MASK`, and `BluetoothDevice.PHY_LE_CODED_MASK`.
`phyOptions`	`int`: preferred coding to use when transmitting on the LE Coded PHY. Can be one of `BluetoothDevice#PHY_OPTION_NO_PREFERRED`, `BluetoothDevice#PHY_OPTION_S2` or `BluetoothDevice#PHY_OPTION_S8`

writeCharacteristic

Added in API level 18
Deprecated in API level 33

public boolean writeCharacteristic (BluetoothGattCharacteristic characteristic)

This method was deprecated in API level 33.
Use BluetoothGatt#writeCharacteristic(BluetoothGattCharacteristic, byte[], int) as this is not memory safe because it relies on a BluetoothGattCharacteristic object whose underlying fields are subject to change outside this method.

Writes a given characteristic and its values to the associated remote device.

Once the write operation has been completed, the BluetoothGattCallback.onCharacteristicWrite(BluetoothGatt, BluetoothGattCharacteristic, int) callback is invoked, reporting the result of the operation.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`characteristic`	`BluetoothGattCharacteristic`: Characteristic to write on the remote device

Returns
`boolean`	true, if the write operation was initiated successfully

Throws
`IllegalArgumentException`	if characteristic or its value are null

writeCharacteristic

Added in API level 33

public int writeCharacteristic (BluetoothGattCharacteristic characteristic, 
                byte[] value, 
                int writeType)

Writes a given characteristic and its values to the associated remote device.

Once the write operation has been completed, the BluetoothGattCallback.onCharacteristicWrite(BluetoothGatt, BluetoothGattCharacteristic, int) callback is invoked, reporting the result of the operation.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`characteristic`	`BluetoothGattCharacteristic`: Characteristic to write on the remote device This value cannot be `null`.
`value`	`byte`: This value cannot be `null`.
`writeType`	`int`: Value is `BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT`, `BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE`, or `BluetoothGattCharacteristic.WRITE_TYPE_SIGNED`

Returns

Returns
`int`	whether the characteristic was successfully written to Value is `BluetoothStatusCodes.SUCCESS`, `BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION`, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, `BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND`, `BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED`, `BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY`, or `BluetoothStatusCodes.ERROR_UNKNOWN`

int

whether the characteristic was successfully written to Value is BluetoothStatusCodes.SUCCESS, BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND, BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED, BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY, or BluetoothStatusCodes.ERROR_UNKNOWN

Throws
`IllegalArgumentException`	if characteristic or value are null

writeDescriptor

Added in API level 18
Deprecated in API level 33

public boolean writeDescriptor (BluetoothGattDescriptor descriptor)

This method was deprecated in API level 33.
Use BluetoothGatt#writeDescriptor(BluetoothGattDescriptor, byte[]) as this is not memory safe because it relies on a BluetoothGattDescriptor object whose underlying fields are subject to change outside this method.

Write the value of a given descriptor to the associated remote device.

A BluetoothGattCallback#onDescriptorWrite callback is triggered to report the result of the write operation.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`descriptor`	`BluetoothGattDescriptor`: Descriptor to write to the associated remote device

Returns
`boolean`	true, if the write operation was initiated successfully

Throws
`IllegalArgumentException`	if descriptor or its value are null

writeDescriptor

Added in API level 33

public int writeDescriptor (BluetoothGattDescriptor descriptor, 
                byte[] value)

Write the value of a given descriptor to the associated remote device.

A BluetoothGattCallback#onDescriptorWrite callback is triggered to report the result of the write operation.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`descriptor`	`BluetoothGattDescriptor`: Descriptor to write to the associated remote device This value cannot be `null`.
`value`	`byte`: This value cannot be `null`.

Returns

Returns
`int`	true, if the write operation was initiated successfully Value is `BluetoothStatusCodes.SUCCESS`, `BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION`, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, `BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND`, `BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED`, `BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY`, or `BluetoothStatusCodes.ERROR_UNKNOWN`

int

true, if the write operation was initiated successfully Value is BluetoothStatusCodes.SUCCESS, BluetoothStatusCodes.ERROR_MISSING_BLUETOOTH_CONNECT_PERMISSION, android.bluetooth.BluetoothStatusCodes.ERROR_DEVICE_NOT_CONNECTED, BluetoothStatusCodes.ERROR_PROFILE_SERVICE_NOT_BOUND, BluetoothStatusCodes.ERROR_GATT_WRITE_NOT_ALLOWED, BluetoothStatusCodes.ERROR_GATT_WRITE_REQUEST_BUSY, or BluetoothStatusCodes.ERROR_UNKNOWN

Throws
`IllegalArgumentException`	if descriptor or value are null